Mod that auto joins channels upon login

Does anyone know of a mod that auto joins specific channels upon login if the character is not already in the channel? For some reason my characters seem to leave channels randomly sometimes upon logging, so I have to rejoin all my channels when I login again.

Just in case someone else has this question again in a year or two. Forget the mod recommended in here, as it does too much stuff. Most of which is done in other chat mods. Simplicity is key. So far, as of the date of this post, nothing autojoins. However, ChannelFu will retain custom channel info. So if you enter a channel to join and monitor in ChannelFu, it will remember that and you can just click it from the menu to join again when you login. Cheers!